Vulcanizing apparatus



Jan. 17, 1928 C. H. ROTH VULCANIZING APPARATUS Filed Sept. 17. 1925INVENTOR Charles H. 20th,

BY WOW ATTORNEY ill ensures H.

1,656,870 n" O FICE,

BOTH, or AKnon or-rro, assrenon TO trrrneoonrnnn TIRE & RUBBER COMPANY,OF AKRON, OHIO, A..COR3?0RATION 0F OHIO.

vuroaurarne arranarcs.

Application filed September 1'7, 19535. Serial No. 56,951.

apparatus without subjecting thetube to objectionable distortion.

In the manufacture of tubular rubber articles, such as inner tubes usedin automobile tires, it has been customary to roll or wind a strip ofraw rubber stool; upon a straight cylindrical mandrel and secure theedges of the stool: by compressing such edges together or by means offabric wrap 'ii-ngs. The assembled mandrel and rubber stock is thenplaced within a heater in order to vulcauize the rubber. Another wellknown method of manufacturing inner tubes consists of up plying rubberstock upon a circular mandrel of substantially the same shape asthetinished inner tube is to assume, and vulcanizing the stock upon thecircular mandrel in a suitable heater. lVhether the rubber stock isvulcanized or cured upon a straight or circular mandrel, manufacturersheretofore have experienced difficulty in removing the vulcanized tubefrom the mandrel, this step in the manufacture being especiallydiflicult in the case of removing cured tubes from circular mandrels.This is. because the tubes being stripped from the circular mandrel aresubjected to considerable stretching and distortion which is likely toinjure the tube permanently.

It is the primary aim of my invention to provide means whereby rubbertubes cured upon a straight or circular mandrel may be strippedtherefrom withoutsubjecting the cured rubber to the objectionablestresses which tend to distort and injure the tube. An apparatusembodying my invention consists generally of a rigid core or mandrelwhich is provided with a pneumatically inflatable member securedlongitudinally thereof, in the event that a straight mandrel.cu'iplnyed, or circuinferentially thereof, in

the event that a circular member is employed. lily invention involvesthe provision of novel means formaintaining the inflatable memher inproper position on the mandrel and for limiting the expansion of thismember. Before the rubber stock is appliedto the mandrel thepneumatic'member is inflated and after the curing process has beencompleted, the pneumatic member is deflated, thereby relieving anytension upon the cured tube and permitting it to beeasily stripped fromthe mandrel. i

I or better understandin of my invention, reference may now be bad tothe accompanying drawing forming a part of this specification, thefigure of which illustrates partly in cross-section and'partly in eleva-'tion, the vulcanizing apparatus embodying my invention. i

in practising my invention I provide a. rigid curved core 1 which formsthe major portion of my vulcanizing apparatus. This core is preferablyconstructed of metal, but it is apparentthatany other suitable rigidmaterial may be employed, and that the member may be either hollow orsolid, without departing from the spirit of my invention. Atthe innercircumferential surface of the curved core I provide av fabric casing 2which is composed of a strip of fabric 3, cemented or glued to the rigidcore 1, and a second strip of fabric dstitched longitudinally along theoutside surface of the strip 3, as indicated at 5.

lit will be observed] that the fabric strip 3 fits snugly against thecore 1 while the fabric strip l: so stitched that considorable slack ispermitted therein in order to provide a space 6 which is adapteditoreceive a pneumatic rubber pad 7. As the ilabric strips 3 and i aresubstantially inextensible, the rubber pad is permitted to expand only alimited degree detern'iined by the amount of slack in the fabric strip4. This prevents any tendency toward overin flation and consequentrupture of the rubber pad 7. One end of the pad 7 is pri'ivided with avalve 8 through-which the pad is in flated and deflated.

After the pad 7 has been secured in proper position within the casing 2and the pad has been inflated to the size indicated in dot and dashlines, rubber tube stock 9 is wrapped about the core and the casing as aunit and the whole assembly is then placed Iii] within a suitablevulcaniainp heater, (not shown). Vi hen the vulcanizing process has beencompleted, the apparatus is removed from the heater and the valve 8 isopened to deflate the padt'. It will be apparent that the cured tube 9,is thus relieved of any tension and that it is loosely disposed aboutthe apparatus. Consequently it may be stripped from the mandrel withoutdifficulty and without subjecting it to material stretching ordistortion.

In the event that it is' desirable to e1nploy a straight mandrel insteadof a curved one, the principles of operation and the structure Of the ap.)aratus will. be substan tially the same as in the case of the ap1aratus described in the foregoing paragraphs. As indicated by dot anddash lines 10 in the figure shown in the drawings. a straight mandrelmay be employed. As the changes in structure from tliecm-ved mandrel tothe straight mandrelare obvious, a further description of the straightmandrel 1 0 is not necessary.

Although I haveillustrated but one preferred forniwhich myinvention mayassmne and have described in detail but a single application thereof, itwill be apparent to those skilled in the'art that the invention is notso limited but that various minor modifications and changes may be madetherein Without departingfrom the spirit of my invention or from thescope of the appended claims.

What I claim is:

1. A vuleanizing apparatus for inner tubes comprising an arcuate mandreland an elongate inflatable member secured to the mandrel substantiallyalong the line of shorter circun'ilerential length thereof.

2. A vulcanizing apparatus for inner tubes comprising a mandrel, anelongate inflatablemembcr and an envelope for connecting the inflatablemember to the man drel.

3. A vulcanizing apparatus for inner tubes comprising a mandrel, anelongate rub. ber pad and an elongate fabric (using on veloping therubber pad and cemented to the mandrel. r r

4;." A vulcanizing apparatus comprising a mandrel, a fabric envelopesecured along one side to said mandrel, and an inflatable memberdisposed within said envelope.

5. The combination with anelongate nlarn drel. of a relatively smallelongate pneumatic pad positioned longitudinally of the mandrel and apair of flexible strips an ranged on opposite sides of the pad andse:cured to the mandrel.

6. A method of manult'acturing inner tubes that comprises Wrapping alayer of rubber stock about a mandrel, imposing pneumatic pressure tospace a longitudinal portion oi? the rubber stock from the mandrel.curing; the rubber stock While so spaced and rollering the pneumatic,pressure to facilitate stripping of the inner tube from the mandrel.

In witness, whereof, signed my name. i

A CHARLES H. ROTH.

I have hereunto

